The prevailing design methodology goals of displays that accompany computing devices (such as smart phones, tablets devices, netbooks, personal data assistants, portable media devices, wearable devices, and even laptops and personal computers) are to achieve slimmer profiles while providing larger display sizes.
For modern display devices such as liquid crystal displays (LCD) or light emitting diode (LED) displays, the display panels are typically implemented as two dimensional pixel arrays, which may be charged (thereby emitting light) in positions and ordered based on the graphical output generated for display.
Conventional display devices are commonly equipped with local storage capabilities, to temporarily pre-load multiple frames of graphical data prior to display. The frames may be presented at a pre-determined (or dynamic) frame rate, often represented as framerate per second (FPS). Similarly, the refresh rate of a display device designates the number of times the graphical data is rendered (drawn) on the display device. Typically, the refresh rate is equal to or higher than the frame rate, such that the same frame may be redrawn one or more times per generation. However, conventional approaches (for LCD devices in particular) of refreshing display panels perform refreshing at pre-determined time intervals, based on the device's capabilities (as specified by the manufacturer), or by an application. This refresh rate is constant even if every pixel in the frame does not change with respect to the previous frame.
Generally, the largest power consuming component in mobile devices with sophisticated graphical and display capabilities is the display panel, which can approach half or more of the device's total power consumption single-handedly. Maintaining a constant refresh rate, and refreshing the entirety of a display panel despite minimal or no pixel changes contribute to the issue by creating inefficient and unnecessary power consumption.